mushrooms

I agree with Jim on the box idea.

Kind of like a fish box when you are introducing a fish after QT to your DT....

That way, it still gets everything it needs, but also enough time to attach w/o anything moving it.

All the above..
And, I've also taken a mushroom (or even lose polyps before), 2 small pieces of rock rubble. I place the mushroom foot between the rocks and rubberband the rocks together creating a snug fit on the foot. I don't rubberband it so tight that it is crushing the foot...just more of a way to keep it stabilized while it attaches.

Good luck!!

I use Jims idea, I take a shallow box put rubble rock in there and put a small screen on top, still gets enough flow on top of my Frag rack but they can't come out. After a few days they attach. I also stick small zoa polyps in there as well if a few come loose from somewhere. Turns out some nice little rubble frags